/// <summary>

        /// 绘制验证码

        /// </summary>

        /// <returns></returns>

        public ActionResult VerificationCode()

        {

            int _verificationLength = ;

            int _width = , _height = ;

            SizeF _verificationTextSize;

            Bitmap _bitmap = new Bitmap(Server.MapPath("~/Skins/Common/Texture.jpg"), true);

            MemoryStream ms = new MemoryStream();

            TextureBrush _brush = new TextureBrush(_bitmap);

            //获取验证码

            string _verificationText = CMS.Common.Text.VerificationText(_verificationLength);

            //存储验证码

            Session["VerificationCode"] = _verificationText.ToUpper();

            Font _font = new Font("Arial", , FontStyle.Bold);

            Bitmap _image = new Bitmap(_width, _height);

            Graphics _g = Graphics.FromImage(_image);

            //清空背景色

            _g.Clear(Color.White);

            //绘制验证码

            _verificationTextSize = _g.MeasureString(_verificationText, _font);

            _g.DrawString(_verificationText, _font, _brush, (_width - _verificationTextSize.Width) / , (_height - _verificationTextSize.Height) / );

            _image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);

            return File(ms.ToArray(), "image/jpeg");  

        }

 /// <summary>

        /// 获取验证码【字符串】

        /// </summary>

        /// <param name="Length">验证码长度【必须大于0】</param>

        /// <returns></returns>

        public static string VerificationText(int Length)

        {

            char[] _verification = new Char[Length];

            Random _random = new Random();

            char[] _dictionary = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '', '', '', '', '', '', '', '', '', '' };

            for (int i = ; i < Length; i++)

            {

                _verification[i] = _dictionary[_random.Next(_dictionary.Length - )];

            }

            return new string(_verification);

        }